The past few years have been an exciting and challenging time of the information age and information channels will form the most important links in the most current message-based enterprises of the future. The computer network systems have become a major part of this evolution. The development of computer network systems goes further by providing message-based communication schemes.
Nowadays, as long as a computer system is powered on, users can use any function which was already installed in the computer system at any time. However, if a user has a time period without using the computer system, the system is still being with power on unless the system is powered off. This consumes system power and conflicts with environment protection. In order to save energy, it is therefore preferable that the computer system can automatically detect the current status of whole system utilization so that it can determine whether some of system components should be powered off. As a result, it greatly saves the electrical power. Moreover, if a new job to be performed is found, the system can be fully powered on automatically, and quickly enters its working state.
For a computer in a network system, if the network is disconnected, data can not be transferred through the network. Therefore, the network communication performance can be greatly improved if the data transfer of a computer is determined first by referring to the current link status of its network system.
Polling is one of conventional methods of communicating important timely message for a computer network system. Software polling is a traditional way to query the link status of a physical layer chip (PHY) for a network device. In the design of this approach, a management frame (as defined in the IEEE 802.3u standard) is transmitted to the MII (Media Independent Interface) management interface for asking a PHY the link status information. The software must fill the management frame by bit by bit. It is thus not efficient. Alternatively, automatically polling through the hardware can be an efficient way to accomplish the same functionality and reduce the loading of software.
Another traditional way to query the link status of a network device is to poll a status register inside the PHY when its polling function is enabled and the polling to the status register stops only when the polling function is disabled. The MII is thus occupied and not available to other jobs. As a result, it defers reading other registers.
From the foregoing discussions of prior arts, it can be seen that the disadvantages as pointed out earlier make the conventional approach inappropriate for a computer system to detect the status about its communications links. There exists a strong need for having a more efficient method and apparatus for a computer system to automatically detect the network link status (link on or link loss) about its communication links so that the computer system can operate in a proper mode accordingly and achieve the power saving features.